Explanation:
Conventional current will flow anticlockwise due to the orientation of the cell. To determine the force experienced by a current carrying conductor in a magnetic field, use (any appropriate hand-rule convention or) Flemming's left hand rule which states that if we arrange our thumb, forefinger and middle finger of the left-hand perpendicular to each other, then the thumb points towards the direction of the force experienced by the conductor, the forefinger points towards the direction of the magnetic field and the middle finger points towards the direction of the electric current.

Explanation:
I is correct as the gravitational force is given by F=GMm/r^2

II is incorrect because gravitational field strength is the gravitational acceleration, which is not equivalent to the force.

III is correct because the gravitational force is the only force acting on the satellite and it provides the centripetal force

Explanation:
The alpha particle has positive charge, therefore its deflection will be in the opposite direction of the electron. (answer A or B)

It has a larger mass, therefore the acceleration will be much smaller, explained by the following calculation:

• qE=ma
• a=qE/m

The alpha particle has twice the charge of the electron, this doubles its acceleration.

It has much more mass than the electron, therefore the denominator in the above ratio increases by a larger factor than the numerator. This means the acceleration of the alpha particle will be much smaller than that of the electron. (its motion will change at a slower rate).

This can also be explained by 2-dimensional motion where there is no force on the horizontal but there is a smaller force on the vertical, meaning it will cover the vertical distance in a longer time, allowing it to travel further along the horizontal, giving the path in B.

Explanation:
According to Newton's third law, the two objects exert equal and opposite forces on each other.

The equation

• Fg=GMm/r

also shows that the forces on the planets are equal in magnitude.

Explanation:

Statement I is incorrect. This is due to Newton’s Law of Gravitation. The astronaut will experience gravitational force from the Earth that acts as the centripetal force.

Since the centripetal force is the gravitational force, then the centripetal acceleration is equal to the gravitational field strength at that point. Therefore both the astronaut and the space station experience the same acceleration. Then statements II and III are correct.

Explanation:
Choice A is incorrect as it equates the gravitational field strength with the gravitational force and these two are two different physical quantities.

Choice B is the correct answer, since the gravitational field strength equals to force per unit mass; g=F/m.

Choice C is incorrect, because the gravitational field strength is inversely proportional to the square of the distance between the center of mass of the planet and that point; g=GM/r^2.

Choice D is incorrect, because the gravitational field strength depends on the mass of the planet; g=GM/r^2.

Explanation:
The pattern of equipotential surfaces belongs to two like charges. That indicates that field direction at points A and B should be in the same direction. Additionally, field lines and equipotential surfaces are at right angles to each other. The only answer that satisfies these conditions is A. Therefore, the answer is A.

1/4

Explanation:
I: A can only be kinetic energy as kinetic energy is always positive

II: B is the total energy as it has the same magnitude as the kinetic energy but is negative, and the sum of the value of graph A and graph B at all times

III: C is the gravitational potential energy as given in the data booklet (Ep=−GMm/r), therefore the statement is wrong

• ε=BvL
• power = ε^2/R=[(BvL)^2]/R=B^2v^2L^2/R

Explanation:
The electric field strength direction is the same as the direction of the electric force.

The electric field will be directed out of the rod in all directions, as it contains uniformly distributed positive charges.

Getting the vector sum for the electric field, due to symmetry the total electric field strength will be directed out of the rod with an angle away from the midpoint of the rod as shown

Also we can think of B as the only correct solution, because it’s a positively charged rod, so the direction must be out of the rod.

Explanation:
Because the electric field is only in the vertical direction, it does not affect the electrons' horizontal speed.

As described by E=F/q in the data booklet, the electrons do experience a vertical force which causes them to accelerate vertically.

Therefore when they enter the electric field, the horizontal speed of the electrons remains the same while their vertical speed increases

Explanation:
The strong nuclear force is the strongest of the four fundamental forces, then comes electromagnetic, then weak nuclear force and finally gravitation

Explanation:

When the bar magnet moves towards and away from the ring, the magnetic flux through the ring will change. According to Lenz's law, an emf, and therefore a current is induced to oppose the change in the flux. So as the bar magnet approaches the metal ring, the metal ring moves to the right due to repulsive forces that resist the decrease in distance between the ring and the magnet. Likewise, as the bar magnet moves away from the metal ring, the metal ring moves to the left.

Explanation:
Summing the four electric field vectors from the individual point charges, the fields from the charge at the top left and the bottom right will cancel out. The fields from the bottom left and top right will add together to give a net field in the direction of the charge in the top right.

According to Fleming’s left hand rule, the electrons in the rod experience a force towards Side B at the top of the rod. The flow of electrons (negative charges) towards the top end of the rod will stop when the electrons at that end are numerous enough to push new electrons back by electrostatic repulsion. That is, an electric field is established in the rod where the top is negative and the bottom is positive. The corresponding field is from the bottom to the top (Side D to Side B)

Explanation:
The gravitational field strength varies inversely with the square of the distance from the center of the planet ($R$) to a given point.

g=GM(R)^2

This means the variation of the gravitational field strength with $R$ is an inverse square law. Note, however, that the question asks for the relationship from the distance from the surface of the planet, therefore the graph starts at a finite value of field strength at the surface ($r=0$), then follows the shape of an inverse square curve.

Explanation:
Centripetal acceleration of an orbiting satellite is the gravitational acceleration of the planet, which is given by

g=GM/r^2

Since the gravitational acceleration is inversely proportional to the square of the orbital radius, the correct graphical representation is given in C

Explanation:

Induced emf is proportional with rate of change in magnetic flux. As the distance between the bar magnet and loop magnetic flux changes and the rate of change increases as the relative velocity increases (vL>vK=vM).

Therefore, εL>εK=εM

Explanation:
The electric field vector inside a hollow conductor is zero. Due to the lack of field inside the sphere, the electric potential is constant and equal to the surface value . Outward from the surface of the sphere, the electric field varies with the inverse square of the distance from the center while electric potential decreases inversely with the distance from the center.